Abstract: A power converter controller includes a drive signal generator coupled to generate a drive signal to control switching of a power switch to regulate a flow of energy to a power converter output in response to an energy requirement of a load. A voltage supply rail is coupled to supply a voltage to the drive signal generator. The supplied voltage is used by the drive signal generator to generate the drive signal. A control circuit is coupled to generate a power down signal that stops the supply of the voltage to the drive signal generator to stop the generation of the drive signal and the control of the switching of the power switch for a period of time. Timer circuitry determines a duration of the period of time and triggers the control circuit to restart the supply of the voltage by the supply rail to the drive signal generator.

Abstract: An example controller includes a comparator coupled to receive a feedback signal representative of an output of the power converter. A counter is coupled to receive an output of the comparator and a feedback sampling signal. The counter is coupled to sample the output of the comparator in response to the feedback sampling signal. A state machine is coupled to receive a feedback time period signal. The state machine is coupled to control switching of the power converter according to one of a plurality of operating conditions in response to the counter and the feedback time period signal. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is coupled to be updated in response to the feedback time period signal.

Abstract: An example power converter includes a first winding, a second winding, a switch, and a controller. The second winding is magnetically coupled to the first winding and the switch is coupled between the first winding and the second winding such that a current flows through the first winding, the second winding and the switch when the switch is in an ON state. The controller is coupled to control the switch to regulate an output of the power converter in response to a feedback signal.

Abstract: A control circuit includes a drive signal generator controlling switching of a power switch to regulate a flow of energy to one or more loads coupled to a power converter output. A regulator circuit charges a capacitor to a first voltage and stops charging the capacitor if an energy requirement of the one or more loads falls below a threshold. The regulator again charges the capacitor after the capacitor is discharged from the first voltage to a second voltage. An unregulated dormant mode control circuit renders dormant the drive signal generator and the regulator circuit while the capacitor is discharged from the first voltage to the second voltage causing the regulation of the flow of energy to the power converter output to cease. The drive signal generator and the regulator circuit are powered up after the capacitor is discharged from the first voltage to the second voltage.

Abstract: A method and apparatus of reducing peak current variation with changing input line voltage in a switch mode power supply is disclosed. An example method includes sensing a current through a switching device of the switch mode power supply. A variable current limit threshold is generated, which increases from a first level to a second level during an on time of the switching device. The current is compared to the variable current limit threshold. A feedback signal representative of an output voltage of the switch mode power supply is sensed. The switching device is controlled in response to the feedback signal and said comparing the current to the variable current limit threshold.

Abstract: An implementation of an unregulated dormant mode with an output reset controller in a power converter is disclosed. An example method for controlling an output of a power converter includes generating a drive signal with a drive signal generator to regulate a flow of energy to one or more loads coupled to an output of the power converter in response to an energy requirement of the one or more loads. The drive signal generator is rendered dormant to cease for a first time period the regulation of energy flow to the one or more loads when the energy requirement of the one or more loads falls below a threshold value. The energy requirement of the one or more loads is not responded to during the first time period. The drive signal generator is then powered up to resume after the first time period has elapsed the regulation of energy flow to the one or more loads. After the first time period has elapsed, it is identified whether there is an increase in the energy requirement of the one or more loads.

Abstract: A power converter with low power consumption during a standby operating condition. An example power controller includes a main converter coupled to a dc input of the power converter to control a transfer of energy from the dc input of the power converter to a main output of the power converter. A standby converter is also included and is coupled to the dc input of the power converter to control a transfer of energy from the dc input of the power converter to a standby output of the power converter during a standby operating condition of the power converter. A standby circuit is also included and is coupled to the dc input of the power converter and coupled to the main converter. The standby circuit decouples the main converter from the dc input of the power converter during the standby operating condition of the power converter.

Abstract: A method of operation for flyback power converter includes operating a controller of the flyback power converter in a regulation mode when a control signal is below a first threshold. The control signal is provided as an input to a terminal of the flyback power converter. When the control signal is below a second threshold and above the first threshold, the controller is operated in a limiting mode. The controller is operated in an external command mode when the control signal is below a third threshold and above the second threshold. Lastly, when the control signal is above the third threshold, the controller is operated in a protection mode.

Abstract: A method, in a power supply controller, of responding to an increase in current through a terminal of the power supply controller, is disclosed. The method includes regulating the terminal to a first voltage level and sensing a magnitude of a first current through the terminal while the controller is regulating the terminal to the first voltage level. The method also includes providing an initial response by the power supply controller in response to the magnitude of the first current exceeding a first threshold current level and then regulating the terminal to a second voltage level after the magnitude of the first current exceeds the first threshold current level. The magnitude of a second current through the terminal is sensed while the controller is regulating the terminal to the second voltage level and the controller determines a final response based on the magnitude of the second current.

Abstract: An example controller includes a feedback sensor circuit that receives a feedback signal representative of an output of a power converter. A feedback sampling signal generator is coupled to generate a feedback sampling signal. The feedback sensor circuit samples the feedback signal in response to the feedback sampling signal. A state machine controls switching of a switch of a power converter circuit according to one of a plurality of operating condition states in response to the feedback sensor circuit. Each of the plurality of operating condition states includes a substantially fixed switch on time. A feedback time period signal generator generates a feedback time period signal received by the state machine. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is updated in response to the feedback time period signal.

Abstract: A controller for use in a power converter includes a control circuit coupled to control switching of a power switch coupled between a positive input supply rail of the power converter and an energy transfer element input of the power converter. A sampling circuit is coupled to the control circuit and is coupled to receive a signal across the energy transfer element input during an off time of the power switch to provide a sampled output of the converter. The sampled output of the power converter is disabled from being resampled by the sampling circuit during an on time of the power switch. A switch conduction scheduling circuit is included in the control circuit and is coupled to the sampling circuit such that the control circuit is coupled to switch the power switch in response to the sampled output of the power converter.

Abstract: An example power supply controller includes a regulation circuit, a current sense circuit, and a response circuit. The regulation circuit is coupled to regulate a sense terminal to a voltage level. The current sense circuit is coupled to the sense terminal to sense a current through the sense terminal a measurement delay period after a magnitude of the current through the sense terminal reaches a first threshold current level. The response circuit is coupled to the sense circuit and is responsive to the current through the sense terminal only after the measurement delay period.

Abstract: An example power converter includes an energy transfer element, a switch, a controller, and a current offset circuit. The controller switches the switch between an ON state and an OFF state to regulate the output of the power converter and is adapted to terminate the ON state of the switch in response to a switch current flowing through the switch reaching a switch current threshold. The current offset circuit is coupled to the input to be directly powered from an input voltage of the power supply. The current offset circuit generates an offset current to flow through the switch only during the ON state of the switch in response to a magnitude of the input voltage. The input current of the power converter is adjusted in response to the offset current.

Abstract: A control circuit includes a drive signal generator controlling switching of a power switch to regulate a flow of energy to one or more loads coupled to a power converter output. A regulator circuit charges a capacitor to a first voltage and stops charging the capacitor if an energy requirement of the one or more loads falls below a threshold. The regulator again charges the capacitor after the capacitor is discharged from the first voltage to a second voltage. An unregulated dormant mode control circuit renders dormant the drive signal generator and the regulator circuit while the capacitor is discharged from the first voltage to the second voltage causing the regulation of the flow of energy to the power converter output to cease. The drive signal generator and the regulator circuit are powered up after the capacitor is discharged from the first voltage to the second voltage.

Abstract: A power supply control circuit for use in a power supply is disclosed. An example power supply control circuit includes a power switch coupled between first and second terminals. The first terminal is to be coupled to a positive input supply rail of the power supply. The second terminal is to be coupled to an energy transfer element input of the power supply. A sampling circuit is coupled to a third terminal. The sampling circuit coupled to sample a signal across the energy transfer element input of the power supply during an off time of the power switch to provide a sampled output of the power supply. The sampled output of the power supply is disabled from being be resampled by the sampling circuit during an on time of the power switch. A control circuit coupled to the sampling circuit and the power switch, the control circuit coupled to switch the power switch in response to the sampled output of the power supply.

Abstract: An implementation of an unregulated dormant mode with an output reset controller in a power converter is disclosed. An example method for controlling an output of a power converter includes generating a drive signal with a drive signal generator to regulate a flow of energy to one or more loads coupled to an output of the power converter in response to an energy requirement of the one or more loads. The drive signal generator is rendered dormant to cease for a first time period the regulation of energy flow to the one or more loads when the energy requirement of the one or more loads falls below a threshold value. The energy requirement of the one or more loads is not responded to during the first time period. The drive signal generator is then powered up to resume after the first time period has elapsed the regulation of energy flow to the one or more loads. After the first time period has elapsed, it is identified whether there is an increase in the energy requirement of the one or more loads.

Abstract: A switch is coupled to a control circuit and to an input of a power converter. The control circuit is coupled to drive the switch in a first operating mode to transfer energy from the input to an output of the power converter when an electrical energy source is coupled to the input of the power converter. The control circuit is coupled to drive the switch in a second operating mode when the electrical energy source is uncoupled from the input. A capacitance is coupled between input terminals of the input of the power converter and is discharged to a threshold voltage in less than a maximum period of time from when the electrical energy source is uncoupled from the input terminals. The control circuit is coupled to drive the switch to have a high average impedance in the first operating mode.

Abstract: A control circuit for use in a power converter with an unregulated dormant mode of operation is disclosed. In one aspect a power converter includes a drive signal generator that is coupled to generate a drive signal to control switching of a power switch coupled to the control circuit to regulate a flow of energy to an output of the power converter in response to an energy requirement of one or more loads coupled to the output of the power converter. A regulator circuit is coupled to charge a capacitor. The capacitor determines a time period. The regulator circuit is coupled to not charge the capacitor if the energy requirement of the one or more loads coupled to the output of the power converter falls below a threshold. The regulator is coupled to again charge the capacitor after the time period has elapsed.

Abstract: An example power converter includes an energy transfer element, a switch, a controller, and a current offset circuit. The controller switches the switch between an ON state and an OFF state to regulate the output of the power converter and is adapted to terminate the ON state of the switch in response to a switch current flowing through the switch reaching a switch current threshold. The current offset circuit is coupled to the input to be directly powered from an input voltage of the power supply. The current offset circuit generates an offset current to flow through the switch only during the ON state of the switch in response to a magnitude of the input voltage. The input current of the power converter is adjusted in response to the offset current.

Abstract: An example controller includes a feedback sensor circuit that receives a feedback signal representative of an output of a power converter. A feedback sampling signal generator is coupled to generate a feedback sampling signal. The feedback sensor circuit samples the feedback signal in response to the feedback sampling signal. A state machine controls switching of a switch of a power converter circuit according to one of a plurality of operating condition states in response to the feedback sensor circuit. Each of the plurality of operating condition states includes a substantially fixed switch on time. A feedback time period signal generator generates a feedback time period signal received by the state machine. A period of the feedback time period signal is substantially greater than a period of the feedback sampling signal. The state machine is updated in response to the feedback time period signal.